Online PHP editor | refs for FlhL3

@ 2013-04-20T12:57:14Z

<?php
	$interval = new DateInterval('P1M');

	$dt = new DateTime('first day of January 2011');
	var_dump($dt);

	$dt->add($interval);
	var_dump($dt);

	$dt = new DateTime('first day of January 2011');

	$dt->sub($interval);
	var_dump($dt);